[Serialization] Add some useful assertions (#19125)
[Serialization] Add some useful assertions (#19125)

This helped me track down the problem in SR-8656, if not the solution.
gribozavr/swift,austinzheng/swift,apple/swift,tkremenek/swift,austinzheng/swift,sschiau/swift,glessard/swift,devincoughlin/swift,shahmishal/swift,harlanhaskins/swift,brentdax/swift,karwa/swift,glessard/swift,xwu/swift,nathawes/swift,xedin/swift,shajrawi/swift,benlangmuir/swift,parkera/swift,tkremenek/swift,rudkx/swift,devincoughlin/swift,austinzheng/swift,roambotics/swift,atrick/swift,danielmartin/swift,danielmartin/swift,alblue/swift,CodaFi/swift,xedin/swift,parkera/swift,JGiola/swift,harlanhaskins/swift,roambotics/swift,nathawes/swift,JGiola/swift,parkera/swift,practicalswift/swift,harlanhaskins/swift,aschwaighofer/swift,aschwaighofer/swift,glessard/swift,CodaFi/swift,alblue/swift,xedin/swift,roambotics/swift,shahmishal/swift,ahoppen/swift,tkremenek/swift,allevato/swift,devincoughlin/swift,lorentey/swift,devincoughlin/swift,apple/swift,rudkx/swift,gribozavr/swift,xedin/swift,danielmartin/swift,danielmartin/swift,shajrawi/swift,devincoughlin/swift,stephentyrone/swift,parkera/swift,airspeedswift/swift,austinzheng/swift,brentdax/swift,apple/swift,stephentyrone/swift,shahmishal/swift,atrick/swift,xwu/swift,practicalswift/swift,apple/swift,jmgc/swift,ahoppen/swift,gregomni/swift,jckarter/swift,austinzheng/swift,practicalswift/swift,shahmishal/swift,alblue/swift,lorentey/swift,jckarter/swift,sschiau/swift,jmgc/swift,glessard/swift,nathawes/swift,brentdax/swift,sschiau/swift,shahmishal/swift,hooman/swift,CodaFi/swift,xwu/swift,gregomni/swift,nathawes/swift,xwu/swift,amraboelela/swift,jckarter/swift,tkremenek/swift,karwa/swift,apple/swift,allevato/swift,parkera/swift,parkera/swift,hooman/swift,gregomni/swift,brentdax/swift,lorentey/swift,aschwaighofer/swift,gregomni/swift,gribozavr/swift,shajrawi/swift,jckarter/swift,practicalswift/swift,atrick/swift,shahmishal/swift,karwa/swift,nathawes/swift,hooman/swift,parkera/swift,roambotics/swift,ahoppen/swift,jmgc/swift,gribozavr/swift,lorentey/swift,rudkx/swift,tkremenek/swift,ahoppen/swift,danielmartin/swift,JGiola/swift,tkremenek/swift,CodaFi/swift,airspeedswift/swift,harlanhaskins/swift,glessard/swift,nathawes/swift,alblue/swift,airspeedswift/swift,xwu/swift,jckarter/swift,shahmishal/swift,gribozavr/swift,danielmartin/swift,xedin/swift,practicalswift/swift,xedin/swift,ahoppen/swift,apple/swift,aschwaighofer/swift,danielmartin/swift,amraboelela/swift,shajrawi/swift,sschiau/swift,hooman/swift,hooman/swift,brentdax/swift,shahmishal/swift,benlangmuir/swift,benlangmuir/swift,austinzheng/swift,allevato/swift,stephentyrone/swift,atrick/swift,allevato/swift,benlangmuir/swift,stephentyrone/swift,lorentey/swift,gregomni/swift,xwu/swift,sschiau/swift,airspeedswift/swift,brentdax/swift,devincoughlin/swift,allevato/swift,rudkx/swift,shajrawi/swift,tkremenek/swift,JGiola/swift,shajrawi/swift,harlanhaskins/swift,jmgc/swift,devincoughlin/swift,karwa/swift,gribozavr/swift,atrick/swift,austinzheng/swift,amraboelela/swift,CodaFi/swift,jmgc/swift,allevato/swift,JGiola/swift,rudkx/swift,gregomni/swift,shajrawi/swift,stephentyrone/swift,devincoughlin/swift,jckarter/swift,jmgc/swift,practicalswift/swift,JGiola/swift,xedin/swift,stephentyrone/swift,sschiau/swift,amraboelela/swift,airspeedswift/swift,ahoppen/swift,jckarter/swift,xedin/swift,karwa/swift,sschiau/swift,xwu/swift,lorentey/swift,glessard/swift,practicalswift/swift,rudkx/swift,karwa/swift,practicalswift/swift,CodaFi/swift,amraboelela/swift,aschwaighofer/swift,alblue/swift,aschwaighofer/swift,aschwaighofer/swift,karwa/swift,stephentyrone/swift,roambotics/swift,airspeedswift/swift,alblue/swift,allevato/swift,hooman/swift,amraboelela/swift,harlanhaskins/swift,alblue/swift,parkera/swift,lorentey/swift,brentdax/swift,shajrawi/swift,gribozavr/swift,atrick/swift,lorentey/swift,benlangmuir/swift,nathawes/swift,CodaFi/swift,roambotics/swift,hooman/swift,karwa/swift,airspeedswift/swift,amraboelela/swift,gribozavr/swift,jmgc/swift,harlanhaskins/swift,sschiau/swift,benlangmuir/swift